Radio antenna apparatus



April 12, 1938. w E NEWMAN 2,113,740

RADIO ANTENNA APPARATUS Filed Nov. 27, 1934 2 Sheets-Sheet l N INVENTOR Will Liam ENewman ATTORNEY Anril 12, 1938. w. E. NEWMAN 2,113,740

RADIO ANTENNA APPARATUS .Filed Nov. 27, 1934 2 Sheets-Sheet 2 INVENTOI? VVi'lliam ENewman Patented Apr. 12, 1938 PATENT OFFICE RADIO ANTENNA APPARATUS William E. Newman,

by mesne assignmen of America, New York,

Delaware Moorestown, N. J., assignor,

ts, to Radio Corporation N. Y., a corporation of Application November 27, 1934, Serial No. 754,964

2 Claims.

This invention relates to radio antenna apparatus, and more particularly to a device which comprehends in one unit a strain insulator, an antenna transformer, and a transformer housing.

Present day practice in the installation and use of antenna systems dictates a need for improved facilities for anchoring an antenna wire under tension at a point where it may be desirable to provide a transformer having a grounded shield to encase the same. It is desirable that a unitary structure be provided both for insulating the antenna wire at a point of anchorage under tension, and also for making the various connections which are necessary between one or more antenna wires, the primary of a transformer, and whatever lead-in wires may be necessary for utilization of the antenna system.

Accordingly, it is among the objects of my invention to provide radio antenna apparatus which shall be serviceable both as an insulator and as a shielded transformer.

Another object of my invention is to provide an assembly of very simple units such as will enable one to properly insulate the energy collecting arms of an antenna system from its means of support, while at the same time providing anchorage for the lead-in wires and a grounding wire, if any, when brought to the point where energy is to be taken off from the antenna arms.

The foregoing and other objects and advantages of my invention will be more fully understood upon reference to the following detailed description when taken in connection with the accompanying drawings, in which Figure 1 shows in elevation a view of one embodiment of my invention assembled with an antenna wire, a lead-in wire, a grounding wire and a suspension wire tied to a suitable support;

Fig. 2 is a view in cross section of the apparatus shown in Fig. 1;

lg. 3 shows diagrammatically a preferred circuit arrangement for which my antenna apparatus is suitable;

Fig. 4 is a cross sectional view of a modified form of my combined insulator and transformer housing;

Figs. 5 and 6 show respectively different views of still another modification of my invention which is particularly adapted for use in connection with a dipole antenna;

Fig. 7 is a plan view of a combined insulator and transformer housing also suitable for use with a dipole antenna; and

Fig. 8 shows a View in elevation of the embodiment otherwise shown in Fig. '1.

Referring to Figs. 1 and 2, I show a strain insulator l which may be made of any material that has suitable strength, insulating properties, and that will withstand weather conditions. For example, porcelain suggests itself naturally, and also other commonly used refractory materials, any of which may be chosen according to prefer ence. This insulator has an umbrella-like configuration with lugs 3 disposed diametrically opposite one another. In each lug is an orifice 5 for attaching one or more wires. Near the center of the umbrella are two holes adapted to receive rivets 1 whereby a metal cap 9 may be mounted on the under-side. This cap preferably has a threaded portion into which may be screwed a shield can H. The shield can has an orifice for admittance of an insulating bushing [3 within which are inserted the various leads for connection with a transformer l5. The bushing l3 and the leads may, if desired, be submerged in a bath of weather-proofing compound so as to fill up the interstices between the entering leads.

The transformer l5 has at least one primary and one secondary, although in certain instances additional windings may be required. The primary i8 is usually connected at one terminal through a short lead H with an antenna wire !9. If a nearby grounding means or other coun- U terpoise is available, such, for example, as the metallic pipe or other structure 2| shown in Fig. 1, then the other terminal of the primary, as well as one terminal of. the secondary 23, may be connected by a short lead 25 to such ground. Otherwise these terminals of the primary and secondary may both be connected to a metallic shielding 21 for the usual down-lead wire 29.

The shielding can ll may be grounded in any suitable manner as shown at 3| in Fig. 3. At the receiver end of the lead-in wire 29 any suitable coupling device, such. as the transformer 33, may be provided. The shielding 21 which surrounds the lead-in wire may also be grounded at the point 35. Other details of the circuit arrangements as shown in Fig. 3 are conventional and form no part of the present invention. Merely for the purpose of illustrating the various advantages of my apparatus, however, I have ineluded in this diagram the representation of a lightning arrestor, such as the spark-gap indicated at 31. In case of an arc discharge across this gap the primary winding I6 would be shortcircuited and protected. This lightning arrestor is also shown in Fig. 2.

In Fig. 4, I have shown an insulator in combination with a transformer housing, the design being more particularly useful where transformer windings of the doughnut, or pancake type are provided. In this embodiment there are two insulator members 39, each having an eyeleted lug 4! for attachment of the necessary wires. The two halves of the insulator housing are fitted together with an intervening gasket 43 and upon final assembly with their contents a metallic ring 45 may be formed about the periphery to permanently seal them together.

Any suitably designed transformer, such as shown at 41, may be supplied within the insulators 39. Holes for admittance of the wires connecting with the transformer may be provided as shown at 49.

The'modification of my invention shown in Figs. 5 and 6 differs from thatshown in Fig. 4 fundamentally in that additional provision is made for attachment thereto of a plurality of antenna arms such as are required in a multiple dipole antenna system. 'Here, again, the transformer housing is formed of two complementary insulating portions 5|. Each of the lugs 53 has a plurality of holes therein for receiving the several wires of the antenna arms. Any suitable transformer arrangement may be housed within the enclosure. Fig. 5 has been drawn to indicate a portion of one insulator 5i broken away for showing a transformer 15. Usually it is preferable to string antenna leads 55 and 57 under tension from suitable supports and to permit these wires to cross one another on opposite sides of the insulators 5i. After further anchorage through the lower holes 59 the wires SI and 63 may be stretched or hung substantially in a vertical plane in which the antenna arms 55 and 5'! also lie. The downwardly extending arms GI and 63 may be supported at their further extremities in any suitable manner. One desirable arrangement is that shown in an application Serial No. 722,842, filed April 28, 1934, by Landon and Reid. The particular utility of my invention in connection with a double dipole antenna system may be appreciated upon noting how the crossed wires of the antenna arms may be kept suitably insulated from one another by being carried through different holes 65 and 67, respectively. These holes are preferably made in the solid portions of the insulator 5! so that the antenna wires do not traverse the transformer chamber. Admittance of the necessary leads to the transformer is obtained by the provision of other holes 69 whereby connections may be made with the wires Bi and 63, respectively. The down-lead which may consist of a twisted pair, shielded, if desired, is represented at H. Access of this cable to the transiormer chamber is provided by an orifice in the metallic ring 45 and by a hole formed in the joint between the two complementary halves 5! of the insulator;

The modification shown in Figs. 7 and 8 combines some of the advantageous features of the two embodiments otherwise shown in Figs. 1, 2, 5 and 6. This modification is'particularly adapted to conditions where considerable space is required for the transformer arrangement. Accordingly, a shield can II is provided and. this is adapted to screw into a shield cap 3, which, in turn, is riveted by means of the rivets I to the body of the insulator 13. This insulator is in one piece and has two lugs 53 diametrically opposed to one another. Each of the lugs has holes 59 therein for anchoring the antenna wires thereto.

Since it is usual to string four antenna arms in such manner as to form a cross-over at the insulator 13, and since it is desirable to insulate one dipole from another, it will be seen that my antenna structure as shown in this embodiment lends itself readily to the requirements. One of the wires 55 may be tied through an upper hole in one of the lugs 53 and brought around on one side of the insulator to a lower hole 59 in the opposite lug 53a. A symmetrical arrangement is iurther provided by tying the wire 51 through the upper hole in the lug last mentioned and bringing it around to a lower hole in the lug first mentioned. In order to hold these wires in place as they'circulate around the rim of the umbrella, bosses are provided. The remaining details of construction as shown in Figs. 7 and 8 will be clearly understood in view of the foregoing descriptionof the other embodiments.

It will be noted from the particular arrangement of the lugs on the insulators as I have shown them in the drawings, that considerable stability of the device is obtained. It is desirable that the transformer should be so mounted as to be free from a swaying motion such as would result if it were suspended from the antenna wire. Furthcrmore, in the modifications shown in Figs. 1, 2, 7 and 8 the transformer structure iscompletely shielded by means of the can H and its cover 9. The device as shown lends itself to manufacture at low cost. Its weather-proof features, its strength, and its durability constitute further advantages.

Although specific embodiments of my invention have been disclosed and described herein, it is to be understood that these are merely illustrative of numerous embodiments which might suggest themselves to those skilled in the art. My invention, therefore, is not to be limited except insofar as is necessitated by the prior art and by the spirit of the appended claims.

I claim as my invention:

1. Radio antenna apparatus comprising a plurality of dipole arms, an insulating member having oppositely extending suspension lugs, said lugs being adapted for tying said dipole arms thereto, a metal cap secured to said insulating member, a metal housing removably secured to said cap and having an orifice therein, a transformer system entirely enclosed in and shielded by said cap and housing, and means issuing through said orifice for suitably connecting said transformer to diiferent ones of said dipole arms and tea utilization circuit.

2. Apparatus in accordance with claim 1, further characterized in that said metal cap and metal housing are grounded.

WILLIAM E. NEWMAN.

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